Process for electrically welding the longitudinal joints in tubular objects.



Nd- 843,515. PATENTED FEB. 5, 1907.

E. BIBR. PROCESS FOR BLEGTRIGALLY WELDING THE LONGITUDINAL JOINTS INTUBULAR OBJECTS. APPLICATION FILED SEPT.10.1906.

UNITED STATES PATENT OFFICE.

EMIL BIEB, OF LONDON, ENGLAND. PROCESS FOR ELECTRICALLYZWELDING THELONGI TUDINAL JOINTS lN TUBULAR OBJECTS.

Specification of Letters Patent. Patented Feb. 5, 1907.

Application filed September 10, 1906. Serial No. 333,914.

To (all whom it may concern:

Beit known that I, EMIL BIER, a citizen of the German Empire, and aresident of London, England, have invented anew and useful process forelectrically welding the longitudinal joints of. tubular objects, suchas boiler shells, tubes, pipes and the like, of which the following is aspecification.

This invention relates to a processfor electrically welding thelongitudinal joints of tubular objects'-such as boiler shells, tubes,pipes, and the likeby applying the alternatmg-current transformer, wereby secondarg current in the object itself is produced, e fecting atthe joint to be welded the desired heat with the highest resistance.

In the accompanying drawings, Figure 1 is a plan view of an arrangementfor welding a boiler-shell. Fig. 2 is a partly-sectioned the weldedjoint.

front elevation. Fig. 3 is the prepared joint of a boiler-shell to bewelded, and Fig. 4 is a is the primar coil, being pushed over onepole-piece of t e magnetic frame 0.

b is the object to be welded together, the longitudinal edges of whichare suitably prepared, as shown in Fig. 3.

'means of which a is the armature, being hinged to the magnetic frame 0,so that it can be lifted up when the object is to be pushed over therespective pole-piece of the ma netic frame.

In order to press tie longitudinal edges of the'o'bject to be weldedtogether against each other, an adjustable clampin device. (1 isprovided, by means of which t e pressure is transmitted to the joint,and thus the edges become forced together by a power of about one-horsepower. In order to maintain the edges being welded together at allpartitions in a close contact, tongs f are provided, by a slightto-and-fro motion to the, edges in their longitudinal direction isimparted.

The operation, respectively the welding, takes place as follows: Thealternating ourprimary coila produces in the object to be weldedtogether, which is to be thought as the secondary coil,

a current, on account of which a warming of f the object to be Weldedtogether takes place.

The highest resistanceis produced at the angle-point of the edges, asshown in where the heating is the highest one. With the increase of thetemperature the resistance is increased as well, so that thelongitudinal edges of the boiler-shell.or the like are at last inwelding heat and'the welding simultaneously on the whole length of theed es of the object takes place. After the welding the joint has theappearance as shown in Fig. 4. I

Having now fully described my invention, what I claim, and desire tosecure by Letters Patent, is

1. A process for electrically welding the longitudinal joints of tubularobjects, such as boiler-shells, tubes, pipes and the like, by means ofinduction-current, produced within the tubular objects consisting inthat the tubular object embodies the secondary coil of analternating-current transformer, substanpose set forth.

2. In a rocess for electrically welding the longitudinal joints oftubular objects, such as boiler-shells, tubes, pipes and the like, bymeans of induction-current produced within the tubular objects, thelongitudinal edges of said objects being formed to obtuse angles andressed against each other during the welding process, substantially asdescribed and shown and for the purpose set forth.

3. In a process for electrically welding the longitudinal joints oftubular objects, such as boiler-shells, tubes, pipes and the like, bymeans of induction-current produced Within the tubular objects, thecombination of means by which besides the tangential pressure, a slightto-and-fromotion is imparted to the edges to be welded, substantially asdescribed and shown and for the purpose set forth.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing Witnesses.

EMIL BIER.

Witnesses:

O'rro KLAUsEn, H. D. JAMEsoN.

Fig. 3,

